Evaluation of implant-abutment microgap and bacterial leakage in five external-hex implant systems: an in vitro study.

PURPOSE: The aim of the present study was to verify the presence of a microgap between implants and prosthetic abutments on their external surfaces in five different external-hex implant systems and to determine whether bacterial leakage occurs through the implant-abutment (I-A) interface. MATERIALS AND METHODS: Ten samples of each implant system were used. Eight samples of each implant system were inoculated with 0.3 µL of a suspension of Escherichia coli for bacterial leakage evaluation. Two other samples were used as controls. Sample analysis was accomplished at 24 and 48 hours and on the 5th, 7th, and 14th day after inoculation. After microbiologic analysis, all samples were prepared for I-A interface evaluation by scanning electron microscopy. The mean of the microgap misfit was obtained from six points at x1,000 and x3,000 magnifications. RESULTS: The Neodent implant system (0.51 ± 0.39 µm) showed the closest adaptation, followed by Dentoflex (1.44 ± 0.73 µm), Titanium Fix (1.88 ± 1.28 µm), SIN (2.46 ± 3.38 µm), and Conexão (2.68 ± 3.02 Μm). Twenty-five percent of the Dentoflex samples showed bacterial leakage through the I-A interface; no other implant system presented bacterial leakage. CONCLUSION: The width of the microgap at the I-A interface was less than 3 µm in all systems. A direct correlation between bacterial leakage and I-A interface misfit was not observed.

Avaliação da adaptação e capacidade de infiltração microbiana na interface implante/pilar / Evaluation of fit and bacterial leakage at implant-abutment interface at different implant systems

Esta pesquisa objetivou avaliar a capacidade de infiltração bacteriana e a desadaptação vertical ao longo da interface implante/pilar protético e classificar a desadaptação vertical e horizontal nos pontos externos da interface, segundo uma nova proposta. Material e métodos: 40 implantes de cinco sistemas nacionais foram inoculados com Escherichia coli e colocados em meio de cultura para observação da infiltração em um, dois, cinco, sete e 14 dias pela turvação do mesmo. Posteriormente, as amostras foram embutidas e desgastadas para avaliação da desadaptação ao longo de toda a interface em microscopia eletrônica de varredura. Resultados: somente um dos sistemas apresentou infiltração bacteriana em 25% das amostras. Os menores valores da desadaptação foram para o sistema Neodent (0,51 μm ± 0,39) e Dentoflex (1,44 μm ± 0,73), seguidos do Titanium Fix (1,88 μm ± 1,28), SIN (2,46 μm ± 3,38) e Conexão (2,68 μm ± 3,02). Os Tipos II e IV da classificação para o desajuste vertical e horizontal foram predominantes. Concluiu-se que todos os grupos apresentaram desadaptação ao longo da interface em pelo menos um dos seis pontos avaliados entre implante e pilar protético. O aumento da desadaptação, nesta interface, não é o único fator determinante para a ocorrência do infiltrado bacteriano, devendo-se levar em consideração a extensão da área de acoplamento na interface e quanto à classificação da desadaptação, o Tipo I, que é a desejada, só ocorreu em 7,5% das amostras.

This study aims to access bacterial leakage capacity and vertical misfit along the prosthetic implantabutment interface and classify the vertical and horizontal misfits at the external interface points, according to a new proposal. Materials and methods: 40 implants of five commercial implant manufacturers were inoculated with Escherichia coli and placed in a culture medium to observe the leakage within 1, 2, 5, 7, and 14 days through media cloud. After, the samples were fitted and the implant-abutment interface evaluated by scanning electron microscopy. Results: Only one of the systems showed bacterial infiltration in 25% of the samples. The lowest values of misfit were presented by Neodent- 0.51 ± 0.39 μm and Dentoflex systems- 1.44 ± 0.73 μm, followed by Titanium Fix - 1.88 ± 1.28 μm; SIN 2.46 ± 3.38 μm and Conexão - 2.68 ± 3.02 μm. Types II and IV of the classification for the vertical and horizontal misfits were predominant. The conclusion was that all groups presented misfit along the interface of at least one of the six points evaluated between the implant and the prosthetic abutment. Increased misfit in the interface is not the only determining factor for occurrence of the bacterial leakage. Also, it must be taken into account the extent of the coupling interface, and concerning the classification of the misfit, type I, which is the most desired, occurred only in 7.5% of the samples.

Reconstrução de rebordos alveolares com xenoenxertos e membranas de e-PTFE / Reconstruction the alveolar ridge whith bonegraft and e-PTFE membranes

O presente trabalho foi desenvolvido com a finalidade de abordar os aspectos gerais da reconstrução de rebordos alveolares com xenoenxerto associado à membrana de e-PTFE, para este fim foi realizada uma revisão da literatura. Foram encontradas várias propostas para alcançar este objetivo, desde o uso somente de membranas sem preenchimento do defeito, associação de membrana e xenoenxerto, associação de membrana e xenoenxerto com osso autógeno particulado e, associação de membrana com preenchimento com osso autógeno particulado. Os resultados, de acordo com o objetivo deste trabalho, mostraram que a associação da membrana de e-PTFE e do osso mineralizado bovino (Bio-Oss®) foi eficiente na formação óssea e que as partículas deste são substituídas por novo tecido num prazo que varia de três a sete meses

The work’s main goal is to reach of alveolar ridge augmentation techniques with xenograft associated to e-PTFE membranes. In which many proposals could be found, since the use only of the membrane without the defect filling, as well as the association of the membrane and xenograft, or the membrane together with xenograft and autogenous bone chips, or just the membrane with the autogenous bone chips. The results, according to this work’s main objective, showed that the association of the e-PTFE membrane with the inorganic bovine bone (Bio-Oss®) was efficient in the bone formation and that its particles are replaced by new tissue in a time that ranges from three to seven months